Pipe brush



FIG. 1 is a front elevation view of a pipe brush;

FIG. 2 is a rear elevation view thereof;

FIG. 3 is a left-side elevation view thereof;

FIG. 4 is a right-side elevation view thereof;

FIG. 5 is a top plan view thereof;

FIG. 6 is a bottom plan view thereof; and,

FIG. 7 is a perspective view thereof.

The article is shown with a symbolic break in its length. The appearance of any portion of the article between the break lines forms no part of the claimed design. 

CLAIM The ornamental design for a pipe brush, as shown and described. 